Corundum-bearing pebble-gravel alluvium is in the floodplain and on the first and second terraces above the floodplain, which forms a valley placer deposit, 1.4 km long and 120 m wide.
The placer deposit contains rounded grains of pink, blue, light blue and violet sapphire
(1.5 to 10 mm). Some are flattened with partially preserved smooth crystal faces.
Ref: E. Ya. Kievlenko, Geology of gems, 2003, p. 62